I am setting up a model which simulate this process: a heating source on a solid metal surface to create a melting pool, then same metal powder will be injected in the melting pool, and this whole thing is put in an argon enviroment.

I want to get the interface between the liquid metal and solid metal, the interface between the liquid metal and argon, and I want to see the deposition of the powder, that the metal powder is also melted and mass transfer into the melting pool.

I used VOF+Injection+Melting/Solidification model, it won't work well.

What other method can I choose? or Is there any specific detail I should pay attention to?